Disclosed embodiments include a receiver having an input that receives a frequency shift key (FSK) signal having a preamble comprising preamble symbols, a phase compensator that applies a compensation vector to one of first and second samples of a first preamble symbol, wherein applying the compensation vector to the one of the first and second samples produces a compensated sample, a demodulator that determines a phase offset between the compensated sample and the other one of the first and second samples of the first preamble symbol, and a frequency offset mapper that determines a frequency offset based at least upon the phase offset. The receiver applies the frequency offset to the FSK signal.